Serious problem with finding lands

Lumpybrass

Private
Minuteman
Dec 15, 2018
53
23
Loading Hornady brass and ELD match 140 gr for a Ruger RPR.
Using two methods of measuring (cleaning rod and the bolt lift) I measure 3.030" cartridge base to ogive, including the Horady comparitor.
Now this places the bullet deep into the case. In fact the barrel of the bullet barely protrudes pass the case mouth.
Using a Hornady rig (not sure just now what it is called, has a drilled and tapped case) with solid contact on the shoulder and good contact with the lands, I get a reading of 3.240". A dummy round seated at that length looks normal.
The Hornady value dummy will not chamber. Chambering a light neck tension dummy pushes the bullet into the case to 3.030".
So, am I looking at two problems? One with a short throat and another with measurement methods?

I am experienced at handloading and feel fairly certain that there is not cockpit error here.
Contacting Ruger is my best more at this point.
Just wondered if you folks ever ran into an incorrect cut chamber.
It is hard to believe I have here but can not think of what else I'm looking at.

Time for a cigar and relax time.


Post thread
 
Take an empty non primed sized piece of brass, seat to an ogive measurement 2.5-2.8 and try and chamber the round. If it sticks pull it out and seat .010 deeper and continue till it does close. Try that and if you get there I will walk you through one more step to help narrow in your land measurement. Looking at my notes using a Hornady comparetor measurement to ogive at 3.0anything seems really long. My eld load hits the lands at 2.55 obviously different chamber and different set of calipers but a .5" difference is massive.

The bullet puller will come into play in part 2.
 
So bolt won't close on what would be 2.020 correct? Try seating deeper .010 until the bolt will close I'm curious what Depth will finally clear but it does indeed sound like the cut the throat too short.
 
The bolt closes at 3.030". Minus the comparitor, that would be 2.020". I measured this diamention (excluding the Hornady rig) and verified with seating the bullet on bolt closing.
 
Ah gotcha that sounds better. Pull the bullet out, resize the brass neck, then seat the bullet to 2.040 and color the o give back black with a sharpie. Now reseat and see if it closes...I keep repeating this process until I see land marks on the bullet then slowly back off by seating deeper until the marks stop showing up on the bullet.
 
To cut to the chase here, maybe my question should be to owners of Ruger RPR's is the cartridge base to ogive max length 2.030" , or close to it?
It caught me by surprise as a legit measurement.